A study to define the possible etiologic role of herpesviruses in huma prostatic neoplasia is being conducted. Benign and malignant prostatic and urinary bladder specimens are being cultivated in vitro. Efforts to transform prostate and other human cells with freshly isolated cytomegaloviruses (CMV) have been successful and the transformed cells are being characterized. Cell cultures are being examined by immunofluorescence, including the anti-complement test, for the presence of infectious CMV as well as for subviral precursors. Methods to promote virus rescue including cocultivation techniques and chemical induction are currently in routine use. Attempts at detection of herpesvirus DNA sequences employing molecular hybridization are demonstrating CMV genomes in the transformed cells. The search for a CMV-nuclear antigen as a marker of transformation is underway and screening of patients' sera will be conducted to detect correspondng antibodies in selected populations. BIBLIOGRAPHIC REFERENCES: Rapp, F., Geder, L., Murasko, D., Lausch, R., Ladda, R. Huang, E., and Webber, M. Long-term persistence of cytomegalovirus genome in cultured cells of prostatic origin. J. Virology, 16: 982-990, 1975. Sanford, E.J., Rohner, T.J., and Rapp, F. Virology of prostatic cancer. Proc. National Prostatic Cancer Project Workshop, in Cancer Chemotherapy Reports, 59: 33-38, 1975.